共查询到18条相似文献，搜索用时 140 毫秒
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速生人工林种植面积大,生长周期短,在取代天然林资源方面具有得天独厚的产量优势,但存在结构疏松、密度小、强度低等缺陷,导致其使用范围大受限制。使用无机材料对人工速生材进行改性处理可有效提高速生材性能和用途。文中简要总结无机质复合木材制备方法——扩散法、溶胶—凝胶法和真空浸渍法,以及无机材料改性处理对速生木材在力学性能、尺寸稳定性、阻燃性、表面疏水性和表面耐候性方面的改善,以期为人工林速生材无机材料改性提供技术参考。 相似文献
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SiO2在木材中能提高木材机械、物理强度,克服各向异性、易燃、易腐、尺寸不稳定等缺陷.研究了有关木材中SiO2的含量及分布的情况;分析了影响木材中SiO2含量的主要因素,如土壤中无机元素的含量、树龄、树木的生长对矿质元素的需求和木材密度等;阐述了木材中SiO2含量对木材的物理力学性质的影响和作用;对今后的研究提出了方向. 相似文献
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在纳米材料特征、制备方法、纳米复合材料等方面研究成果的基础上,国内外的学者对木材无机纳米复合材料进行了初步研究.研究表明,木材内部具有容纳纳米粒子的纳米空间,它存在于木材细胞壁上的微细纤维之间;并存在能与纳米粒子结合的活性基团;可用溶胶-凝胶法(sol-gel)、原位插层合成法、注入填充法等方法,形成木材/无机纳米复合材料;木材原有性能均能有不同程度的提高,甚至有可能产生全新的性能.基于木材的特点,以木材/无机纳米复合材料的工业化研究为目标,分析木材/无机纳米复合材料的制备、检测与分析表征的研究现状,提出研究建议与展望,主要包括无机纳米材料的筛选、表面改性和分散处理、纳米粒子与木材复合的途径和复合机理研究、木材/无机纳米复合材料的结构表征和性能分析及其应用研究等. 相似文献
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要实现木材-无机质复合材的人工模拟,其关键还是在于研究和探讨木材生物矿化的机理,因此要对木材中无机物的情况进行研究,从而获取生物矿化所形成的木材/无机质复合材料的形成机理,以此来指导木材的生物改性或木材/无机复合材的仿生合成。本文采用光学显微镜对几种木材/二氧化硅生物矿化复合材中硅石的分布进行观察发现:硅石主要分布在木射线细胞中,大量的晶体在木射线细胞以及轴向薄壁细胞中均有分布;采用重量法对几种木材/二氧化硅生物矿化复合材中二氧化硅含量情况进行测定表明:子京、山油柑、柚木、柠檬桉、山竹子等5种木材/二氧化硅生物矿化复合材中二氧化硅含量分别为1.5106%、0.8941%、0.8654%、0.2155%、0.1676%。 相似文献
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介绍了用无机纳米材料改性木材及所获复合材料体系的形成过程、复合机理等方面的研究进展。包括:木材-无机纳米复合材料纳米尺度的形貌、结构观测与表征,采用电镜技术、能谱技术进行其的组成和化学价态的表面分析,采用微区FTIR分析技术测定纳米粒子在该材料体系中的分布及与木材组分的结合状态,用波谱分析的方法,分析纳米粒子在木材组份中的固着机理。 相似文献
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溶胶-凝胶法在木材/无机纳米复合材料上的应用 总被引：4，自引：0，他引：4
对溶胶-凝胶过程的影响因素、溶胶-凝胶法在木材/无机纳米复合材料上的应用、木材/无机纳米复合材料的性 能等方面加以评述,总结了当前研究中存在的一些问题,并提出了今后的研究方向。 相似文献
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溶胶-凝胶法制备木材/无机复合材料研究现状及进展 总被引：3，自引：0，他引：3
本文简要介绍了溶胶-凝胶法的基本原理、生产工艺以及国内外应用溶胶一凝胶法制备木材／无机复合材料的研究现状，并指出了溶胶-凝胶法在木质复合材料制备上现存的问题。 相似文献
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从木材细胞壁主要化学组分角度,归纳了木材湿热软化机理;总结了以木材密实化技术（整体密实化与表层密实化）、木材大变形加工技术（实木弯曲）和木材焊接（无胶胶合）技术为典型代表的木材湿—热—力改性技术的特点和应用情况,并对今后湿—热—力改性技术的研究与应用提出几点建议。 相似文献
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柠檬桉木材中二氧化硅的分布和含量的测定 总被引：5，自引：0，他引：5
生物矿化所形成的木材-无机质复合材是当前木材科学研究的热点之一，要实现木材一无机质复合材的人工模拟，其关键还在于研究和探讨木材生物矿化的机理，因此要对木材中无机物的分布及其含量进行研究，从而获取生物矿化所形成的木材一无机质复合材料的形成机理，以此来指导木材的生物改性或木材一无机复合材的仿生合成。本研究采用光学显微镜对柠檬桉木材中二氧化硅的分布进行观察，得出柠檬桉木材中二氧化硅主要分布在射线细胞中，同时大量的晶体存在于轴向薄壁细胞中，早材中的硅石多于晚材中的硅石。采用重量法对木材轴向分布、径向分布中灰分和二氧化硅的含量进行的分析表明：柠檬桉木材中灰分和二氧化硅的含量随着高度的增加而降低，柠檬桉木材灰分和二氧化硅的含量从边材部位向心材部位逐渐减少。 相似文献
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Summary In a study on the SiO2 wood-inorganic composites prepared by the sol-gel process with tetraethoxysilane (TEOS), it is more appropriate to use safer agents than TEOS, considering the operational and processing environments. In this study, therefore, methyltrimethoxysilane (MTMOS) was used to prepare the SiO2 wood-inorganic composites, and comparative studies were made with TEOS. Resultingly, SiO2 wood-inorganic composites could be successfully prepared from MTMOS reaction system, as in TEOS system, with its lower concentration, and both composites had SiO2 gels specifically formed within the cell walls from moisture-conditioned wood specimens. On this SiO2 composites, the water-repellent properties were added most effectively with a molar ratio of 2-heptadecafluorooctylethyltrimethoxysilane (HFOETMOS) to alcohol being 1/250 and 1/180 for TEOS and MTMOS reaction systems, respectively. On the other hand, fire-resisting properties were tried to add to SiO2 composites with several fire-resisting agents. The fire-resisting agents in the obtained composites are not, however, stable and leached out readily. Therefore, a small addition of HFOETMOS was tested to the MTMOS and TEOS reaction systems with fire-resisting agents. The obtained results clearly indicated that HFOETMOS could restrain the fire-resisting agents to be leached from the composites, and that composites from MTMOS system were superior to TEOS system on the antileachability. Therefore, MTMOS can be appropriate for displacement of TEOS as a chemical agent to prepare SiO2 wood-inorganic composites.This research has been performed in Department of Wood Science and Technology, Faculty of Agriculture, Kyoto University, Kyoto, Japan.This research was supported by a Grant-in-Aid for Scientific Research (B) (No. 06453176, 1994.4–1996.3) from the Ministry of Education, Science, and Culture, Japan. 相似文献
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Summary A study of the wood-inorganic composites prepared by the sol-gel process with a metal alkoxide indicated that an inorganic modification of wood with TiO2 gels from tetraisopropoxytitanium (TPT) can not improve its properties due to the formation of the gels in the cell lumina by high hydrolysis rate of TPT. In this study, therefore, titanium alkoxides or titanium chelates which have the lower rate of hydrolysis and subsequent polycondensation than TPT were used for preparing TiO2 wood-inorganic composites to study the topochemical effects of the TiO2 gels for the property enhancement of wood. As a result, it was found by SEM-EDXA analysis that the TiO2 gels deposited within the cell walls could improve the properties of wood in dimensional stability and fire-resistance, whereas for the gels in the cell lumina, property enhancement could not be achieved, as observed in SiO2 wood-inorganic composites.This research has been performed in Dept. of Wood Sci. & Technol., Kyoto UniversityThis research was supported by a Grant-in-Aid for Scientific Research (B) (No. 06453176, 1994.4–1996.3) from the Ministry of Education, Science, and Culture, Japan. The authors were grateful to Nippon Soda Co., Ltd. for providing titanic reagents. 相似文献
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Nanoscale in Wood,Nanowood and Wood—Inorganic Nanocomposites 总被引：4，自引：0，他引：4
ZhaoGuangjie LuWenhua 《中国林学(英文版)》2003,5(1):44-48
In order to introduce nano science and technology(NST) into the research field of wood science and technology,and promote the research of wood science and wood-inorganic composites to nanoscale ,some new concepts,such as the nano space in wood,nano structure units of wood and nanowood are put forward in this paper based on the layer structure of wood cell wall and the pile-up model of its main components.Furthermore,the process of preparing nanowood is discussed,and wood-inorganic nanocomposites may be operated in three ways with wood (matrix) and inorganic filler phase in 0-2,0-3 or 2-3 dimensions respectively.The following results are obtained:(1) The nanoscale voids in wood indicate that wood has inherent space to accommodate nanosized materials,such as nanoparticles,nanotubes and nanosticks;(2) According to the size from top down,the nano structure units in wood can be classified as :nanolayers,nano CMF (cellulose microfibril) and matrixd,nano crystallite units and cellulose chain clusters,and these can theroretically from nanowood;(3) The preparation of wood-inorganic nanocomposites can be operated on 0-2,0-3 or 2-3 dimensions. 相似文献
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For enhancing fire-resistant properties, a binary system to prepare wood-inorganic composites was studied by adding sodium methoxide (SM) or sodium acetate (SA) to a reaction system for SiO2 composites. Compared with the SiO2 composites, both the Na2O-SiO2 composites prepared could be greatly improved up to 600°C-700°C (glowing). From scanning electron microscopic observations, this enhanced fire resistance was assumed to be due to chemical and physicochemical effects, such as dehydration and carbonization of wood by Na2O gel. The glassy layer and intumescent structure formed over the cell walls were thought to prevent oxidation and heat transfer from proceeding into the inner portion of the wood cell walls. However, the reaction medium with SM to prepare Na2O-SiO2 composites was basic, whereas that with SA was rather neutral. In addition, in the latter composites, most of the inorganic gel was formed within the cell wall, retaining the porous structure characteristic of wood. Therefore, the Na2O-SiO2 composites prepared with SA can be concluded to be preferable for practical purposes.Part of this report was presented at the 50th annual meeting of the Japan Wood Research Society, Kyoto, April 2000 相似文献
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溶胶-凝胶法功能性改良木材研究进展 总被引：1，自引：1，他引：0
基于木材天然的双重毛细管系统结构,金属醇盐可在木材"微/纳米容器"内进行溶胶-凝胶反应最终制备木材-无机复合材料。在溶胶-凝胶改良木材过程中,以金属醇盐为主要组分的前驱体溶液可通过涂覆、浸渍/真空加压浸渍、微波/超声波辅助等方式对木材进行改性,且木材密度、基材初始含水率、溶胶反应体系、溶胶粒径、溶胶pH值等对木材溶胶-凝胶改性效果都会有一定的影响。文中主要从制备方法和影响因素2个方面对溶胶-凝胶法功能性改良木材的研究现状进行归纳总结,并提出溶胶-凝胶功能性改良木材的应用前景和发展方向。 相似文献
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